Flexible routing policy for Wi-Fi offloaded cellular data

ABSTRACT

A system/router that flexibly routes Wi-Fi offloaded data receives a data packet from a user equipment via an access point of a Wi-Fi network. The data packet includes an access point name (“APN”) and an Internet Protocol (“IP”) address. The system defines two or more routing policies, each routing policy including a routing criteria and a priority. The system evaluates the data packet based on the routing policies, and routes the data packet to one of at least two possible destinations based at least on the routing policies, including the priorities.

FIELD

One embodiment is directed generally to a communication system, and in particular to a communication system for offloading cellular data onto a Wi-Fi network.

BACKGROUND INFORMATION

Mobile data offloading generally refers to the use of complementary network technologies for delivering data originally targeted for cellular networks. Cellular operators perform and encourage offloading to ease congestion of cellular networks. The primary complementary network technologies used for mobile data offloading are Wi-Fi, “femtocells”/“small cells” and Integrated Mobile Broadcast.

An increasing need for offloading solutions is caused by the explosion of Internet data traffic, especially the growing portion of traffic going through mobile networks. This has been enabled by smartphone devices possessing Wi-Fi capabilities together with large screens and different Internet applications, from browsers to video and audio streaming applications. In addition to smartphones, laptops and tablets with 3G/4G access capabilities are also a major source of mobile data traffic. Further, Wi-Fi is typically much less costly to build than cellular networks.

SUMMARY

One embodiment is a system/router that flexibly routes Wi-Fi offloaded data. The system receives a data packet from a user equipment via an access point of a Wi-Fi network. The data packet includes an access point name (“APN”) and an Internet Protocol (“IP”) address. The system defines two or more routing policies, each routing policy including a routing criteria and a priority. The system evaluates the data packet based on the routing policies, and routes the data packet to one of at least two possible destinations based at least on the routing policies, including the priorities.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an overview diagram of a network including network elements that implement embodiments of the present invention and/or interact with embodiments of the present invention.

FIG. 2 is a block diagram of a computer server/system in accordance with an embodiment of the present invention.

FIG. 3 is a DHCP-based message flow setup when interworking with a GGSN in accordance with one embodiment.

FIG. 4 is a DHCP-based message flow setup when interworking with a default gateway, such as a default gateway, in accordance with one embodiment.

FIG. 5 is a UE initiated DHCP-based teardown message flow when interworking with a GGSN in accordance with one embodiment.

FIG. 6 is a DHCP-based initiated release or timeout message flow when interworking with a GGSN in accordance with one embodiment.

FIG. 7 is a DHCP-based GGSN initiated teardown message flow in accordance with one embodiment.

FIG. 8 is an IKE-based message flow setup when interworking with a GGSN in accordance with one embodiment.

FIG. 9 is an IKE-based message flow teardown when interworking with a GGSN that is IKE initiated in accordance with one embodiment.

FIG. 10 is an IKE-based message flow teardown when interworking with a GGSN that is GGSN initiated in accordance with one embodiment.

FIG. 11 is an ePDG based message flow for Initial Attach with GTP on S2b in accordance with one embodiment.

FIG. 12 is an ePDG based message flow for Detach and PDN Disconnection with GTP on S2b in accordance with one embodiment.

FIG. 13 is an ePDG based message flow for handover from 3GPP access (4G/3G) to untrusted Wi-Fi in accordance with one embodiment.

FIG. 14 is an ePDG based message flow for Handover from Wi-Fi access to 3GPP access (3G/4G) in accordance with one embodiment.

FIG. 15 is message flow for AP to AP roaming in accordance with one embodiment.

FIG. 16 is a flow diagram of the functionality of a Wi-Fi offload module of FIG. 2 when performing Wi-Fi offload in accordance with embodiments of the present invention.

FIG. 17 is a flow diagram of the functionality of the Wi-Fi offload module of FIG. 2 when performing a flexible routing policy for Wi-Fi offloaded data in accordance with embodiments of the present invention.

DETAILED DESCRIPTION

One embodiment is a Wi-Fi offload solution which includes a flexible policy based routing that selectively offloads data traffic. Parameters returned from the policy server or information contained in the data packet can be used to make the selective offload decisions.

FIG. 1 is an overview diagram of a network 50 including network elements that implement embodiments of the present invention and/or interact with embodiments of the present invention. Network 50 includes user equipment (“UE”) 53 that is able to connect to a Wi-Fi access point (“AP”) 52. UE 53 may be any device used by an end-user for Wi-Fi communication, including a smartphone, a laptop computer, a tablet, etc. UE 53 may be in communication with AP 52 using known methods. AP 52 is coupled to an access controller (“AC”) 51.

Network 50 further includes a security gateway 60, also referred to as a “multi-service security gateway” (“MSG”), a “wireless access gateway” (“WAG”) or an evolved packet data gateway (“ePDG”), coupled to a “authentication, authorization and accounting” (“AAA”) server 54. Security gateway 60 functions, in general, as a high performance tunneling gateway for heterogeneous networks, while AAA server 54 functions, in general, as a security architecture for distributed systems for controlling which users are allowed access to which services, and tracking which resources they have used. In one embodiment, SG 60 is implemented by a multi-core network processor.

AAA server 54 in embodiments functions in accordance to either Remote Authentication Dial In User Service (“RADIUS” or “Radius”) or “Diameter” protocol specifications. Radius is a networking protocol that provides centralized AAA management for users that connect and use a network service. Diameter is an AAA protocol for computer networks that has largely replaced Radius.

Security gateway 60 is further coupled to an accounting server (“AS”) 55, and a gateway general packet radio service (“GPRS”) support node (“GGSN”) 56. Security gateway 60 is in communication with GGSN 56 through a GPRS tunneling protocol (“GTP”) tunnel 62.

Security gateway 60 is coupled through a default gateway 57 to the Internet 59. GGSN 56 is coupled to a cellular operator's core network 58. A core network, in general, is the central part of a telecommunication network that provides various services to customers who are connected by the access network. The core network is responsible for handling voice/data traffic over the public switched telephone network (“PSTN”), an IP network, or any other combination of networks.

FIG. 2 is a block diagram of a computer server/system 10 in accordance with an embodiment of the present invention. System 10 can be used to implement any of the network elements shown in FIG. 1 as necessary in order to implement any of the functionality of embodiments of the invention disclosed in detail below. Although shown as a single system, the functionality of system 10 can be implemented as a distributed system. Further, the functionality disclosed herein can be implemented on separate servers or devices that may be coupled together over a network. Further, one or more components of system 10 may not be included. For example, for functionality of user equipment, system 10 may be a smartphone that includes a processor, memory and a display, but may not include one or more of the other components shown in FIG. 2.

System 10 includes a bus 12 or other communication mechanism for communicating information, and a processor 22 coupled to bus 12 for processing information. Processor 22 may be any type of general or specific purpose processor. System 10 further includes a memory 14 for storing information and instructions to be executed by processor 22. Memory 14 can be comprised of any combination of random access memory (“RAM”), read only memory (“ROM”), static storage such as a magnetic or optical disk, or any other type of computer readable media. System 10 further includes a communication device 20, such as a network interface card, to provide access to a network. Therefore, a user may interface with system 10 directly, or remotely through a network, or any other method.

Computer readable media may be any available media that can be accessed by processor 22 and includes both volatile and nonvolatile media, removable and non-removable media, and communication media. Communication media may include computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and includes any information delivery media.

Processor 22 may further be coupled via bus 12 to a display 24, such as a Liquid Crystal Display (“LCD”). A keyboard 26 and a cursor control device 28, such as a computer mouse, may further be coupled to bus 12 to enable a user to interface with system 10 on an as needed basis.

In one embodiment, memory 14 stores software modules that provide functionality when executed by processor 22. The modules include an operating system 15 that provides operating system functionality for system 10. The modules further include a Wi-Fi offload module 16 for performing Wi-Fi offloading of cellular data, flexible policy routing, and all other functionality disclosed herein. System 10 can be part of a larger system, such as added functionality to the “Oracle Communications Security Gateway” from Oracle Corp. Therefore, system 10 can include one or more additional functional modules 18 to include the additional functionality. A database 17 is coupled to bus 12 to provide centralized storage for modules 16 and 18.

Wi-Fi Offload Message Flows

FIGS. 3-15 below, in general, are message flows of IP address assignment and data flow setup using DHCP in accordance with embodiments of the invention. FIG. 3 is a DHCP-based message flow setup when interworking with a GGSN in accordance with one embodiment. The message flow is as follows:

1. An IP security (“IPsec”) tunnel is created between AP 52 and SG 60 at the time AP 52 is booted. AP 52 will relay all traffic between UE 53 and SG 60 over the IPsec tunnel. In some embodiments, the IPsec tunnel is an optional feature that is provided when security is desired between AP 52 and SG 60. When the IPsec tunnel is created as needed, all traffic between AP 52 and SG 60 will be protected by IPsec.

2. UE 53 connects to AP 52 over Wi-Fi, and uses Extensible Authentication Protocol (“EAP”)-SIM authentication to authenticate with AAA server 54.

3. The 802.1x connection setup completes, and UE 53 is now connected.

4. UE 53 broadcasts a DHCP Discover message in order to receive an IP address. The DHCP message contains the media access control (“MAC”) address of the UE in the DHCP “chaddr” field.

TABLE 1 DHCPDISCOVER fields (M)andatory, DHCP Message (C)onditonal, Field (O)ptional Field Value “chaddr” M The UE MAC Address. (Client Hardware Address) Client Identifier M Unique ID for client. Option (61) May be set to the MAC. Requested Parameter O Parameters requested of Option (55) the DHCP server.

5. AP 52 acts as a BOOTP/DHCP relay server, and relays the DHCP broadcast towards SG 60.

6. SG 60 receives the DHCP Discover message.

-   -   a. If the address assignment will be done through a local         address pool, SG 60 will assign the UE IP address prior to         contacting AAA server 54. Otherwise, AAA server 54 will be         responsible for assigning the UE IP address.     -   b. The DHCP Discover message is converted into an AAA         Access-Request, which is sent to AAA server 54.

TABLE 2 Radius Access-Request fields (M)andatory, Radius Message (C)onditonal, Field (O)ptional Field Value User-Name M MAC address, taken from DHCP “chaddr” field. Framed-IP- C The IP address that was allocated Address for the UE. Present if the MSG allocated the IP.

7. AAA server 54 receives the Access-Request, and associates the MAC address with UE 53 that is already authenticated over EAP-SIM. If AAA server 54 is responsible for allocating the UE IP address, an IP will be assigned to UE 53. AAA server 54 retrieves the GPRS profile information for UE 53, and responds with an Access-Accept message.

TABLE 3 Radius Access-Accept fields (M)andatory Radius Message (O)ptional Field (C)onditonal Field Value Framed-IP- C Only required in the case that the Address AAA server allocates the IP address. The IP address that was allocated for the UE Framed-IP- O The subnet mask for the UE. Netmask 3GPP-IMSI M The UE IMSI 3GPP-WLAN- M The APN APN-Id Chargeable- M The MSISDN User-Identity 3GPP-NSAPI O The NSAPI 3GPP GPRS QoS O The QoS Profile. Profile Accounting- O Interval at which to send interim Interim- accounting records. Interval Session- O Session-Timeout interval. Used to Timeout determine DHCP lease timers.

8. SG 60 receives the Access-Accept, and generates a DHCP Offer with the IP address that was allocated to UE 53. The profile information is stored in SG 60 to be used when later setting up the GTP tunnel. SG 60 stores the UE's profile returned in Access-Accept from AAA server 54 to be used later when setting up the GTP tunnel or re-authenticating the UE when it roams in and out of the Wi-Fi range.

TABLE 4 DHCPOFFER fields (M)andatory DHCP Message (O)ptional Field (C)onditonal Field Value “yiaddr” (Your M The IP address that was allocated IP Address) for the UE “siaddr” (Server M The DHCP Server IP address on the IP Address) MSG “chaddr” (Client M The UE MAC Address Hardware Address) Subnet Mask M Taken from Framed-IP-Netmask if Option (1) present, or local configuration. Router Option (3) M The default gateway/router Domain Name M DNS server address, configured. Server Option (6) DHCP Server ID M The DHCP Server IP address on the Option (54) MSG DHCP Lease Time M From AAA Session-Timeout, or local Option (51) config. DHCP Renewal O Set to ½ of Lease Time, or Time Option (58) configurable. DHCP Rebinding O Set to 87.5% of Lease Time, or Time Option (59) configurable.

9. AP 52 receives the DHCP Offer, and relays it back to UE 53.

10. UE 53 wishes to accept the DHCP Offer, and sends a DHCP Request message.

TABLE 5 DHCPREQUEST fields (M)andatory, DHCP Message (C)onditonal, Field (O)ptional Field Value “chaddr” (Client M The UE MAC Address Hardware Address) Requested IP Address M The Requested IP Address. Option (50) Requested Parameter O Parameters requested of the Option (55) DHCP server.

11. AP 52 receives the DHCP Request, and relays it to SG 60.

12. SG 60 receives the DHCP Request, and validates that the requested IP address matches the one offered. SG 60 determines that the policy for UE 53 is to route to GGSN 56. SG 60 then initiates the GTP tunnel setup with GGSN 56 by sending a Create-PDP-Context Request to GGSN 56.

TABLE 6 Create-PDP-Context-Request fields (M)andatory, GTP-C Message (C)onditonal, Field (O)ptional Field Value IMSI M 3GPP-IMSI from AAA Access-Accept. NSAPI M From AAA 3GPP-NSAPI, or local configuration. End user M The UE IP address that was allocated. address Access Point M From AAA 3GPP-WLAN-APN-Id. Name QoS M From AAA 3GPP GPRS QoS Profile, or local configuration.

13. GGSN 56 responds with a Create-PDP-Context Response.

14. The GTP-U tunnel is now established. SG 60 programs the flows between the GTP-U tunnel and the IPsec tunnel, if it was previously determined that the IPsec tunnel was needed for security and was previously created.

15. SG 60 sends an Accounting-Request (Start) to AAA server 54.

TABLE 7 Accounting-Request (Start) fields (M)andatory, Radius Message (C)onditonal, Field (O)ptional Field Value Calling-Station- M The MSISDN, taken from ID Chargeable-User-Identity of Access-Accept Framed-IP-Address M The UE IP address Acct-Session-Id M Generated by the MSG. Acct-Status-Type M Start

16. AAA Server 54 responds with an Accounting-Response, acknowledging the request.

17. SG 60 responds to the DHCP Request with a DHCP ACK message. This confirms that the IP address was successfully allocated to UE 53 for use.

18. AP 52 relays the DHCP ACK back to UE 53.

19. UE 53 sends and receives data using the allocated IP address. AP 52 manages routing the traffic to and from SG 60, and SG 60 will route the traffic to and from GGSN 56 over the GTP-U tunnel.

FIG. 4 is a DHCP-based message flow setup when interworking with a default gateway, such as default gateway 57, in accordance with one embodiment. The signaling flows when routing to default gateway 57 are identical to those of FIG. 3 except the Gn′ interface has been removed. Further, in FIG. 4, flows 12-14 of FIG. 3 replaced with the following flow:

12. Based on the UE profile information received from AAA server 54 (i.e., access point name (“APN”)), SG 60 determines that the policy is to route the UE traffic to default gateway 57 instead of GGSN 56 of FIG. 3.

FIG. 5 is a UE initiated DHCP-based teardown message flow when interworking with a GGSN in accordance with one embodiment. The message flow is as follows:

1. UE 53 disconnects from the AP Wi-Fi connection.

2. AP 52 sends an Accounting-Request (Stop) to AAA server 54.

3. AAA server 54 responds back to the Accounting-Request.

4. AAA server 54 associates the accounting stop from AP 52 with the accounting session on SG 60, and generates a Radius Disconnect-Request message to SG 60, with the UE MAC address in the User-Name field.

5. SG 60 initiates GTP tunnel teardown by sending a Delete-PDP-Context request to GGSN 56.

6. GGSN 56 responds back with a Delete-PDP-Context response.

7. SG 60 removes all flow information for GTP and DHCP, and cleans up any active contexts.

8. SG 60 sends an Accounting-Request (Stop) to AAA server 54.

TABLE 8 Account-Request (Stop) fields (M)andatory, Radius Message (C)onditonal, Field (O)ptional Field Value Calling-Station- M The MSISDN, taken from ID Calling-Station-ID of Access-Accept Framed-IP-Address M The UE IP address Acct-Session-Id M Same as in the Start Request Acct-Status-Type M Stop Acct-Input-Octets M # Octets in to the UE Acct-Output-Octets M # Octets out of the UE Acct-Input-Packets M # Packets in to the UE Acct-Output-Octets M # Packets out of the UE

9. AAA server 54 will release the IP address if allocated, and collect any accounting information. AAA server 54 then sends an Accounting-Response (Stop) back to SG 60.

10. SG 60 responds to the Disconnect-Request with a Disconnect-ACK, signaling that all contexts have been cleared.

In another embodiment, a UE initiated DHCP-based teardown message flow is performed with a default gateway, such as default gateway 57, instead of interworking with a GGSN as in FIG. 5. In this embodiment, the message flow is identical to FIG. 5 except flows 5 and 6 are removed.

FIG. 6 is a DHCP-based initiated release or timeout message flow when interworking with a GGSN in accordance with one embodiment. The message flow is as follows:

1. UE 53 may send a DHCP Release message to release the IP address that was allocated. The procedure would be the same as if the DHCP lease or other internal timers expire, so both procedures are covered in this example.

2. AP 52 relays the DHCP Release over the IPsec tunnel. As previously discussed, the IPsec tunnel is optional. If the IPsec tunnel was established during the offload initiation procedure, then the DHCP Release will be sent over the IPsec tunnel. Otherwise, it will be sent without using the IPsec tunnel.

3. SG 60 receives the DHCP Release, or an internal SG timer expires. SG 60 initiates GTP tunnel teardown by sending a Delete-PDP-Context request to GGSN 56.

4. GGSN 56 responds back with a Delete-PDP-Context response.

5. SG 60 removes all flow information for GTP and DHCP, and cleans up any active contexts.

6. SG 60 sends an Accounting-Request (Stop) to AAA server 54 (see Table 8 above).

7. AAA server 54 will release the IP address if allocated, and collect any accounting information. AAA server 54 then sends an Accounting-Response (Stop) back to SG 60.

In another embodiment, a DHCP-based initiated release or timeout message flow is performed with a default gateway, such as default gateway 57, instead of interworking with a GGSN as in FIG. 6. In this embodiment, the message flow is identical to FIG. 6 except flows 3 and 4 are removed.

FIG. 7 is a DHCP-based GGSN initiated teardown message flow in accordance with one embodiment. The message flow is as follows:

1. GGSN 56 initiates GTP tunnel teardown by sending a Delete-PDP-Context request to SG 60.

2. SG 60 responds back with a Delete-PDP-Context response.

3. SG 60 removes all flow information for GTP and DHCP, and cleans up any active contexts.

4. SG 60 sends an Accounting-Request (Stop) to AAA server 54 (see Table 8 above).

5. AAA server 54 will release the IP address if allocated, and collect any accounting information. AAA server 54 then sends an Accounting-Response (Stop) back to SG 60.

Embodiments shown in FIGS. 8-10 below are Internet Key Exchange version 2, under RFC 4306 (“IKE”)-based message flows. These message flows are based on the tunnel terminating gateway (“TTG”) functionality defined in Annex F of 3GPP TS 23.234 V11.0.0 Release 11 3GPP, “System to Wireless Local Area Network (WLAN) interworking”, the disclosure of which is hereby incorporated by reference. In the embodiments, there is an IPsec tunnel from each UE to the SG. The IKE exchanges are consolidated into Request and Response messages for clarity.

FIG. 8 is an IKE-based message flow setup when interworking with a GGSN in accordance with one embodiment. The message flow is as follows:

1. UE 53 connects to AP 52 over Wi-Fi, and uses EAP-SIM authentication to authenticate with AAA server 54.

2. The 802.1x connection setup completes, and UE 53 is now connected.

3. UE 53 attempts to establish an IPsec tunnel to SG 60 using IKE.

4. During IKE negotiation:

-   -   a. If SG 60 is responsible for allocating the UE inner IP, an         address is allocated from a local address pool.     -   b. SG 60 triggers an Access-Request to AAA server 54 in order to         authenticate the user and/or obtain an IP address and GPRS         profile (see Table 2 above).

5. AAA server 54 responds with an Access-Accept, and includes the GPRS profile information, and IP address if allocated (see Table 3 above).

6. SG 60 receives the Access-Accept, and based on the profile information, determines the flow is to GGSN 56.

7. SG 60 initiates the GTP tunnel setup with GGSN 56 by sending a Create-PDP-Context Request to GGSN 56 (see Table 6 above).

8. GGSN 56 responds with a Create-PDP-Context Response.

9. SG 60 sends an Accounting-Request (Start) to AAA server 54 (see Table 7 above).

10. AAA server 54 responds with an Accounting-Response, acknowledging the request.

11. SG 60 completes IKE negotiation with the client, and returns the IP address that was allocated for UE 53. The GTP-U tunnel is now established. SG 60 programs the flows between the GTP-U tunnel and the IPsec tunnel.

12. Data flows over the IPsec tunnel between UE 53 and SG 60, and is routed to and from GGSN 56.

In another embodiment, an IKE-based message flow setup is performed with a default gateway, such as default gateway 57, instead of interworking with a GGSN as in FIG. 8. In this embodiment, the message flow is identical to FIG. 8 except flows 7 and 8 are removed. Instead of establishing a connection with GGSN 56, SG 60 determines that the flow is to a default gateway, and programs the data flow accordingly.

FIG. 9 is an IKE-based message flow teardown when interworking with a GGSN that is IKE initiated in accordance with one embodiment. The message flow is as follows:

1. UE 53 initiates tunnel teardown with SG 60 over IKE.

2. SG 60 initiates GTP tunnel teardown by sending a Delete-PDP-Context request to GGSN 56.

3. GGSN 56 responds back with a Delete-PDP-Context response.

4. SG 60 completes the IKE teardown procedure with the client.

5. SG 60 removes all flow information for GTP and IPsec, and cleans up any active contexts.

6. SG 60 sends a Radius Accounting-Request (Stop) to AAA server 54 (see Table 8 above).

7. AAA server 54 will release the IP address if allocated, and collect any accounting information. AAA server 54 then sends an Accounting-Response (Stop) back to SG 60.

In another embodiment, an IKE-based message flow teardown that is IKE initiated is performed with a default gateway, such as default gateway 57, instead of interworking with a GGSN as in FIG. 9. In this embodiment, the message flow is identical to FIG. 9 except flows 2 and 3 are removed.

FIG. 10 is an IKE-based message flow teardown when interworking with a GGSN that is GGSN initiated in accordance with one embodiment. The message flow is as follows:

1. GGSN 56 initiates GTP tunnel teardown by sending a Delete-PDP-Context request to SG 60.

2. SG 60 initiates IPsec tunnel teardown with UE 53 over IKE.

3. UE 53 responds back to SG 60 and completes the teardown procedure.

4. SG 60 responds back to GGSN 56 with a Delete-PDP-Context response.

5. SG 60 removes all flow information for GTP and IPsec, and cleans up any active contexts.

6. SG 60 sends a Radius Accounting-Request (Stop) to AAA server 54 (see Table 8 above).

7. AAA server 54 will release the IP address if allocated, and collect any accounting information. AAA server 54 then sends an Accounting-Response (Stop) back to SG 60.

Embodiments shown in FIGS. 11-14 below are based on ePDG functionality as defined in 3GPP TS 23.402 V11.4.0 Release 11, “Architecture enhancements for non-3GPP accesses”, the disclosure of which is hereby incorporated by reference. FIGS. 11-14 include a packet data network (“PDN”) gateway (“GW”), and a Home Subscriber Service (“HSS”) which manages the user database for AAA services. FIGS. 11-14 further include a Policy and Charging Rules Function (“PCRF”) for policy control and charging rules. When roaming is involved, the PCRF is referred to as the “hPCRF” in the home network, and “vPCRF” in the visiting network.

FIG. 11 is an ePDG based message flow for Initial Attach with GTP on S2b in accordance with one embodiment. FIG. 12 is an ePDG based message flow for Detach and PDN Disconnection with GTP on S2b in accordance with one embodiment. S2b is the interface connection between ePDG and the PDN gateway.

FIG. 13 is an ePDG based message flow for handover from 3GPP access (4G/3G) to untrusted Wi-Fi in accordance with one embodiment. FIG. 13 includes a Mobility Management Entity (“MME”) which handles the signaling (control plane) related to mobility and security for the E-UTRAN access (LTE access).

1. UE 53 acquires LTE access to the core network.

2. UE 53 initiates the handover procedure and performs the mutual authentication towards the ePDG by using the IKEv2/EAP-AKA.

3. UE 53 is authenticated via a 3GPP AAA server 54.

4. UE 53 requests an IP address in the IKEv2 message exchange. The ePDG creates and sends the “Create Session Request” message containing the IMSI, MSISDN and other parameters to the PDN GW.

6. The PDN GW sends the “Create Session Response” back; this contains the IP address to be assigned to UE 53 (the same IP as was being used by UE on the Radio access network (“RAN”)).

7. The ePDG will return the IP address to the UE using the IKEv2 message exchange. The IPSec and the GTP tunnels are established for the data traffic.

FIG. 14 is an ePDG based message flow for Handover from Wi-Fi access to 3GPP access (3G/4G) in accordance with one embodiment.

FIG. 15 is message flow for AP to AP roaming in accordance with one embodiment. The message flow for FIG. 15 is as follows:

1. In case UE 53 roams from AP1 to AP2, SG 60 will get a DHCP request message from AP2 (once it detects that UE 53 has roamed from AP1) with the IP/MAC of UE 53. Once received, SG 60 will know that the UE is now connected to AP2 and the internal tables of SG 60 are updated.

2. The DHCP ACK is sent back to the AP2.

3. SG 60 will be able to reuse the GTP tunnel on the core side.

Wi-Fi Offload Accounting Support

Embodiments provide accounting support for Wi-Fi offload solutions, such as the solution shown in FIG. 3. This feature enables SG 60 to collect statistics about offloaded data per UE session and send the collected information to external RADIUS and Diameter AAA servers residing in the network.

The Radius accounting start request will be generated from SG 60 per UE 53 to AAA server 54 for the following events:

-   -   1. After MSG gets a GTP-C Create PDP Context Response from GGSN         56;     -   2. In the case of “Routing to Gateway” call flow (as per FIG. 4         above), after SG 60 gets a DHCP request with IP+MAC; or     -   3. In the case of “IKE initiated flow to Gateway” call flow (as         per FIG. 8 above with default gateway), after SG 60 gets an         Access-Accept from AAA server 54.         The start request will contain the attributes disclosed in Table         9 below.

The Radius accounting stop request will be generated from SG 60 per UE 53 to AAA server 54 for the following events:

-   -   1. Once SG 60 gets a GTP-C Delete PDP Context Response from GGSN         56 (as per FIG. 5 above);     -   2. If GGSN 56 is not involved in the call flow, once SG 60         receives a Disconnect-Request with UE MAC from AAA server 54 (as         per FIG. 5 above with default gateway);     -   3. If GGSN 56 is not involved in the call flow, once SG 60 gets         a DHCP release or lease timeout (as per FIG. 6 above with         default gateway);     -   4. If GGSN 56 initiated the tunnel teardown, after SG 60 sends a         GTP-C Delete PDP Context Response (as per FIG. 7 above);     -   5. In case of “IKE initiated tear-down” call flow without GGSN,         after SG 60 sends a IKE tunnel disconnect response (as per FIG.         9 above with default gateway); or     -   6. Any unexpected error happened in the system after Accounting         start record is sent.         The start request will contain the attributes disclosed in Table         9 below.

The following table discloses the Radius attributes in accordance with one embodiment:

TABLE 9 Radius Radius Attribute Attribute Accounting RADIUS Attributes Description Type Value Messages Notes Acct-Status-Type Indicates the 40 1 (start) Start, Interim- beginning (start), 2 (stop) Update, Stop interim, stop of the 3 (interim- tunnel session update) Class This value coming in 25 Application- Start, Interim- Access-Accept specific Update, Stop response from the value server is copied in Accounting requests sent from NAS. Acme-Event-Time Indicates the time the 55 String Start, Interim- This attribute can be event (tunnel containing Update, Stop used to contain establishment/tear time in GMT “Record Opening down/periodic Time” information interim) has occurred. mentioned in CRD Calling-Station-Id The MSISDN of the 31/66 String Start, Interim- The MSISDN, taken UE containing Update, Stop from Chargeable- MSISDN User-Identity of number Access-Accept Framed-IP-Address IP address allocated 8 Address Start, Interim- Inner IP assigned from for the UE Update, Stop either local-address- pool or AAA server. This attribute contains the value of UE-IP- Address attribute User-Name MAC address of the 1 String Start, Interim- UE consisting of Update, Stop MAC Acct-Session-ID Indicates a unique 44 Start, Interim- Accounting ID Update, Stop, On, Off NAS IP-Address Wancom0's IP 4 Start, Interim- IP address of the address Update, Stop, access server (MSG) On, Off NAS Port Ephemeral port to 5 Start, Interim- which external Update, Stop, accounting socket is On, Off bound to NAS Identifier Value configured by 32 Start, Interim- the user in account- Update, Stop, server configuration On, Off Acct-Terminate- Reason for tunnel 49 1-UE Stop Cause tear-down (UE- requested initiated, GGSN 19 - GGSN initiated, DHCP initiated initiated, system 5 - Session error) Timeout (DHCP initiated) 9 - NAS error (System error) Acct-Session-Time Length/Duration of 46 Interim- the UE session Update, Stop Acct-In-Packets # packets in to the 47 Interim- UE Update, Stop Acct-Output-Packets # packets out of the 48 Interim- UE Update, Stop Acct-lnput-Octets # bytes in to the UE 42 Interim- Update, Stop Acct-Output-Octets # bytes out of the UE 43 Interim- Update, Stop Acct-Input- Number of times the 52 Interim- Gigawords Acct-Input-Octets update, Stop counter has wrapped around 2{circumflex over ( )}32 over the course of the session Acct-Output- Number of times the 53 Interim- Gigawords Acct-Input-Octets update, Stop counter has wrapped around 2{circumflex over ( )}32 over the course of the session 3GPP-IMSI IMSI of the user 1 String Start, Interim- 3GPP TS 29.06, Update, Stop section 16.4.7.1 3GPP-GGSN- IP of the GGSN 7 Address Start, Interim- 3GPP TS 29.06, Address server used by the Update, Stop section 16.4.7.1 GTP-C for the Sent only if GGSN is context establishment present in the call flow 3GPP-WLAN-APN-Id The W-APN from 100 String Start, Interim- Using the same which the user Update, Stop attribute type of receives service from Diameter as there is no corresponding radius attribute 3GPP-PDP-IP- IP address of the UE 1227 Address Start, Interim- Using the same Address related to a particular Update, Stop attribute type of PDP context Diameter as there is no corresponding radius attribute. Sent only if GGSN is present in the call flow. This should be same as Framed-IP-address 3GPP-RAT-Type Indicates which RAT 21 Integer (set Start, Interim- 3GPP TS 29.06, is currently serving to WLAN - Update, Stop section 16.4.7.1 the UE 3)

For the Diameter start record, the format of an Accounting-Request (“ACR”) message that SG 60 will send to AAA server 54 in one embodiment is as follows:

<ACR> ::= < Diameter Header: 271, REQ > { Session-Id } { Origin-Host } { Origin-Realm } { Destination-Realm } { Destination-Host } { Accounting-Record-Type } { Accounting-Record-Number } [ Acct-Application-Id ] [ User-Name ] [ Event-Timestamp ] [ Framed-IP-Address ] [ Calling-Station-Id ] [3GPP-IMSI] [3GPP-GGSN-Address] [3GPP-WLAN-APN-Id] [3GPP-PDP-IP-Address] [3GPP-RAT-Type]

-   -   The ACR AVPs:     -   Session-Id AVP (263)—will be used to uniquely identify this         session.     -   Origin-Host AVP (264)—will be populated from the hostname field         in the account-config data object and the origin-realm field and         the domain-name-suffix field in the account-server sub-object         for which server the request is destined to.     -   Origin-Realm AVP (296)—will be populated from the origin-realm         field and the domain-name-suffix field in the account-server         sub-object for which server the request is destined to.     -   Destination-Realm AVP (283)—will be populated by the value of         the Origin-Realm AVP in the CEA received from the server for         this connection.     -   Destination-Host AVP (293)—will be populated by the value of the         Origin-Host AVP in the CEA received from the server for this         connection.     -   Accounting-Record-Type AVP (480)—will be populated by the         appropriate value for what type of accounting message is being         sent, for START records the value is 2.     -   Accounting-Record-Number AVP (485)—This is a value that uniquely         identifies this message in the session. It amounts to a sequence         number for this connection.     -   Acct-Application-Id AVP (259)—will be set to the value of 3,         this the value the base RFC calls for in Diameter based         accounting messages.     -   User-Name AVP (1)—is of type string and contains the MAC address         of the UE.     -   Event-Timestamp AVP (55)—This is the time in seconds that         indicates the time when the GTP tunnel is established.     -   Framed-IP-Address AVP (8)—contains the IP address allocated for         the UE.     -   Calling-Station-Id AVP (31)—This contains the MSISDN of the UE.     -   3GPP-IMSI AVP (1)—This contains the IMSI of the UE.     -   3GPP-GGSN-Address AVP (847)—This contains the IP address of the         GGSN server.     -   3GPP-WLAN-APN-Id AVP (100)—This contains the W-APN Id from which         the user receives service from.     -   3GPP-PDP-IP-Address AVP (1227)—This contains the IP address of         the UE related to a particular PDP context.     -   3GPP-RAT-Type AVP (21)—This contains the RAT that is currently         serving the UE.

For the Diameter stop record, the format of ACR message that SG 60 will send to AAA server 54 in one embodiment is as follows:

<ACR> ::= < Diameter Header: 271, REQ > { Session-Id } { Origin-Host } { Origin-Realm } { Destination-Realm } { Destination-Host } { Accounting-Record-Type } { Accounting-Record-Number } [ Acct-Application-Id ] [ User-Name ] [ Event-Timestamp ] [ Termination-Cause ] [ Acct-Session-Time ] [ Framed-IP-Address ] [ Calling-Station-Id ] [ Accounting-Input-Octets ] [ Accounting-Output-Octets ] [ Accounting-Input-Packets ] [ Accounting-Output-Packets ] [3GPP-IMSI] [3GPP-GGSN-Address] [3GPP-WLAN-APN-Id] [3GPP-UE-IP-Address] [3GPP-PDP-IP-Address] [3GPP-RAT-Type]

-   -   The ACR AVPs:     -   Acct-Session-Time AVP (46)—contains the length of the tunnel         lifetime in seconds. It can only be present in ACR messages for         Interim Record or Stop Record.     -   Accounting-Input-Octets AVP (363)—contains the number of octets         into the UE.     -   Accounting-Output-Octets AVP (364)—contains the number of octets         out of the UE.     -   Accounting-Input-Packets (365)—contains the number of packets         into the UE.     -   Accounting-Output-Packets (366)—contains the number of IP         packets out of the UE.     -   The new 3GPP attributes description is the same as disclosed         above for the Start record.

DHCP IP Address Assignment for Endpoints

In connection with the message flow disclosed in conjunction with FIG. 3 above, SG 60 will mimic the functionality of a DHCP server in order to assign UE IP addresses in one embodiment. In one embodiment, the IP address assignment is as follows:

-   -   In flows 2 and 3 of FIG. 3, UE 53 connects to AP 52 over 802.1x,         and is initially authenticated using EAP-SIM between AP 52 and         AAA server 54.     -   Once UE 53 is connected to AP 52, it will send a DHCPDISCOVER         broadcast message in order to obtain an IP address, as shown in         flow 4 of FIG. 3.     -   AP 52 will be responsible for relaying the DHCP requests between         UE 53 and SG 60. The connection between AP 52 and SG 60 may be         secured with a single IPsec tunnel per AP/SSID. In this case,         the DHCP messages will be relayed over the IPsec tunnel, as         shown in flow 5 of FIG. 3.     -   When SG 60 receives the DHCPDISCOVER request, it will first         determine who is responsible for assigning the IP address. The         method for IP address assignment will be configurable. The         addresses may be assigned through a local address pool in the         same fashion as already implemented for IKE local address pools,         or AAA server 54 can be responsible for assigning the IP         address.     -   If SG 60 is allocating the IP addresses, the address will be         allocated prior to the AAA exchange, otherwise AAA server 54         will return the allocated IP address. SG 60 converts the         DHCPDISCOVER into an Access-Request message, as shown in flow 6         b of FIG. 3.     -   AAA server 54 receives the Access-Request message, and         associates the UE MAC with the UE that already authenticated         with AP 52 using EAP-SIM. If AAA server 54 is responsible for         allocating the UE IP Address, it will assign an IP which will be         returned in the response. AAA server 54 will also query the GPRS         profile information for the user, and return those parameters in         the Access-Accept message sent to SG, as shown in flow 7 of FIG.         3.     -   SG 60 receives the Access-Accept response from AAA server 54,         and converts it into a DHCPOFFER request that is sent towards UE         53. The offer includes the IP address that was allocated for UE         53, as shown in flow 8 of FIG. 3.     -   The DHCPOFFER will be forwarded back to UE 53, and UE 53 will         determine if it wishes to accept the offer. If so, it will send         a DHCPREQUEST message, requesting the IP address that was in the         offer message, as shown in flows 9-11 of FIG. 3.     -   SG 60 receives the DHCPREQUEST message, and validates it against         the offer. If the request is invalid, such as an invalid IP         address, SG 60 responds with a DHCPNAK and the transaction         terminates.     -   Depending on the UE profile information received from AAA server         54, along with local configuration, SG 60 may contact GGSN 56 to         establish a GTP tunnel for UE 53, as disclosed above. When         contacting GGSN 56, a “remote” inner IP address may be assigned         by GGSN 56. In this case, the UE's IP address will be replaced         by this GGSN assigned “inner IP” for the user traffic (GTP data         channel) between SG 60 and GGSN 56.     -   SG 60 may start accounting at this point, as disclosed above.     -   If all flows installed correctly and any GTP tunnels are set up,         a DHCPACK message is sent back to the client, and the client is         free to send and receive data traffic.

FIG. 16 is a flow diagram of the functionality of Wi-Fi offload module 16 of FIG. 2 when performing Wi-Fi offload in accordance with embodiments of the present invention. In one embodiment, the functionality of the flow diagram of FIG. 16, and FIG. 17 below, is implemented by software stored in memory or other computer readable or tangible medium, and executed by a processor. In other embodiments, the functionality may be performed by hardware (e.g., through the use of an application specific integrated circuit (“ASIC”), a programmable gate array (“PGA”), a field programmable gate array (“FPGA”), etc.), or any combination of hardware and software. In general, the functionality of FIG. 16 is implemented by SG 60 of FIG. 1, while interacting with other network elements of FIG. 1.

At 1610, an IP security tunnel is optionally created between AP 52 and SG 60.

At 1620, SG 60 receives a DHCP broadcasted message that was broadcast by UE 53 and relayed by AP 52.

At 1630, SG 60 assigns an IP address through a local address pool for UE 53, or through AAA server 54, and converts the DHCP message into an AAA access request that is sent to AAA server 54.

At 1640, SG 60 receives an AAA access accept from AAA server 54 and generates a DHCP offer.

At 1650, SG 60 receives a DHCP request with an IP address from 1630 and, based on a policy for UE 53, initiates a GTP tunnel setup with GGSN 56.

At 1660, SG 60 programs message flows between the GTP-U tunnel and the IPsec tunnel, if the tunnel is created at 1610.

As disclosed, embodiments provide Wi-Fi offload functionality for cellular data. Embodiments include a DHCP server to process DHCP requests from mobile devices (i.e., UEs) and interact with policy servers (i.e., AAA servers) to authorize UE access and get proper access parameters (e.g., APN, IP, SUBNET MASK, DNS, etc.). Embodiments can assign IP addresses from a local address pool or from the policy server on the UE side (for traffic between the UE and the SG) and optionally, the GGSN can assign an IP address for the UE for traffic between the SG and the GGSN.

Embodiments further include an SG routing agent that can set up the routing decision based on routing policies configured and the parameters from the UE and the policy server. Further, a GTP agent interacts with a DHCP agent to set up GTP tunnel with provisioned GGSN gateway if GTP routing is selected.

In embodiments, once a GGSN server is selected and a GTP tunnel is established, GTP traffic flows (inbound and outbound) are created on a dedicated hardware platform to handle GTP tunnel traffic in real-time to support high throughput. Further, an accounting agent creates various accounting records to accounting servers (e.g., AAA or diameter).

Embodiments further support high availability (“HA”) with HA setup and protects real time traffic from switchovers. All UE's profiles, SG routing decisions, GTP tunnels on hardware, etc. are synchronized to a standby system in real time to guarantee no traffic interruption. Embodiments support IKEv2 and IPsec protection if configured between an AP/Wi-Fi hot-spot and a security gateway access interface. Finally, if a UE can get an IP address from an AP, embodiments support IKEv2/IPSEC between a UE and a security gateway access interface (LTE mode).

As disclosed above, embodiments provide Wi-Fi offload of cellular data to offload traffic from a service provider's Radio Access Network (“RAN”) to IP networks using Wi-Fi connections. Wi-Fi offload offers a cost-effective means of offloading large amounts of mobile data traffic while delivering a variety of new services. As disclosed above, IPsec is optional for Wi-Fi offload in accordance to embodiments. However, some embodiments include a policy based routing of the offloaded Wi-Fi data independent of whether or not IPSec is involved.

In one embodiment, SG 60 includes a routing policy for egress traffic of UE 53 (i.e., data received from UE 53). In this embodiment, each UE is associated with an APN (i.e., an “associated access point name”) or International Mobile Subscriber Identity (“IMSI”) during Wi-Fi signaling. SG 60 will route each UE's traffic based on the associated APN or IMSI. Although APN/IMSI based routing is disclosed, other embodiments can be applied to other identity based routing. Embodiments use an “sg-policy”parameter that can be configured for each APN/IMSI to define how to route traffic for the UEs associated with each particular APN/IMSI. Embodiments may route traffic to a pre-configured GGSN 56 or directly to the Internet.

In one embodiment, during the initialization process of UE 53, such as shown in FIG. 3 above, SG 60 will assign a unique IP address (locally or through AAA server 54) to UE 53 and UE 53 will also be associated with a specific APN/IMSI. The sg-policy configured for the APN/IMSI will indicate where to route the traffic. It can specify to route traffic from UE 53 (based on the assigned IP-APN/IMSI association) to GGSN 56 server (via GTP tunnel 62) or to Internet 59 (through the policy's egress realm). Therefore, as UE 53 finishes signaling, SG 60 has all the information to set-up a message flow for the egress traffic.

Specifically, the IP address assigned to UE 53 from either SG 60 or AAA server 54 is used to match the egress message flow. SG 60 also maintains an association between the UE's IP and its APN/IMSI. From the configured sg-policy for each APN, SG 60 knows the GGSN and its associated User Datagram Protocol (“UDP”) ports. In one embodiment, instead sending traffic to a GGSN, the sg-policy for the UE's APN/IMSI is to route the UE's traffic directly to the Internet 59.

One embodiment provides routing for ingress traffic to UE 53 when GTP-U (GTP user data tunneling) packets come in on the well-known UDP port 2152. As a result, SG 60 can classify the ingress traffic as either GTP-U or non-GTP-U packets. For any traffic coming in from the Internet (non GTP traffic), it would be processed the same way as SG's 60 data pass-through traffic. For the traffic coming in from a GGSN as GTP-U traffic, its GTP/UDP/IP tunnel header needs to be removed first and its inner destination IP (UE's assigned IP) would be used to match the UE's NAT flow for further processing.

One embodiment routes a UE's ingress traffic from GGSN (GTP tunneled packets). In this embodiment, for any inbound packets classified as GTP-U traffic, a “GTP-ingress-process” will be called for inbound GTP processing, which would remove their outer GTP/UDP header and get the inner user data packets (destined to UE's IP addresses). During each UE's signaling (IKE/DHCP/GTP), the UE's assigned IP address, TEID (tunnel endpoint identifier), interface and vlan id, GGSN's IP and port will be sent to the multi-processor core of SG 60 and maintained by an UE hashTable indexed by UE's IP. The GTP-ingress-process does not require the detailed information for an UE, but the information can be used to verify whether the tunneled GTP packet is valid for the UE and the hashEntry for the UE can be used to save statistics for the UE. The GTP-ingress-process does the following:

-   -   Check a GTP packet to see whether it is host bound (GTP-U         error). If yes, the packet will be sent to the host.     -   For GTP-U echo request, the GTP-U response will be formed and         sent out by the ingress port.     -   For GTP-U data pass-through packet, remove its GTP/UDP/IP tunnel         header, switch to a new tag based on its inner destination IP         (unique to the UE).     -   Verify the de-tunneled packet by TEID with UE's IP, GGSN IP and         port, interface/vlan ID.     -   The de-tunneled packet will be matched against the SG's inbound         data pass-through flow and be processed the same way as the SG's         pass-through data packets afterwards.

One embodiment provides flow matching for Wi-Fi offload. With well-known UDP port 2152, or other configured port, defined for GTP-U traffic, SG 60 will classify a GTP-U packet in a UE's inbound packet processing. Once classified as GTP-U, the GTP-ingress-process would be called for GTP-U de-tunneling and the inner IP would be used for nat-flow match and any further processing afterwards. For a UE's outbound traffic, the UE's assigned IP can be used for GTP-egress-process. A simplified GTP-Packet Processing Module (“PPM”) will be defined to handle communication between host and SG 60, and setup hashEntry for a UE dynamically during the UE's signaling process (IKE/DHCP/GTP).

Therefore, embodiments include a flexible policy based routing for traffic originating from mobile users via UE 53 through SG 60, in contrast with the current often used routing for Wi-Fi offload solutions, APN only based routing. Embodiments base the routing on flexible policies for each access interface (or routing realm). Each policy can be configured with a routing criteria, which can be based on APN, the UE's IP network, IMSI, MSISDN, or QOS, or a future application. In addition, each policy is also configured with a priority number so, for example, the lower the number, the higher the priority. If multiple policies are assigned to a routing realm, the policies are matched by the policies' priority. The policy match is flexible as well: it can be “exact match”, a “prefix match” or a “regular expression (“regex” match”) in one embodiment. For example, “[A-Z]123456” would match any string which starts with a capital letter followed by “123456”.

Below are some examples of simplified routing policies to illustrate routing decisions in accordance with embodiments of the present invention:

1. A service provider customer requires that traffic from any UE with an APN of “foo.com” is to be routed to its dedicated GGSN server by GTP tunneling. Further, traffic from other UEs is to be routed to the Internet by a router. As a result, two policies (“gtp-policy” and “internet-policy”) need to be configured for this customer's routing demands.

a> Identifier gtp-policy Priority 1 Match-field apn Match-type exact Match-value foo.com routing-profile-list gtp-profile1, gtp-profile2, gtp-profile3 routing-profile-select hunt b> Identifier internet-policy Priority 10 Match-field none Match-type Match-value Routing-profile-list ip-profile Routing-profile-select

When a UE 53 registers through Wi-Fi with SG 60, it could be assigned the APN value “foo.com”. With the above policies, the traffic from UE 53 would match “gtp-policy” and be routed to a GGSN server with GTP tunneling (depending which gtp-profile to use by “hunt” method). For any other UEs (not assigned with APN “foo.com”), the traffic would be routed to a router defined by “ip-policy”. The policy “internet-policy”, “match-field none” acts as a default policy for traffic.

2. An enterprise customer requires that UE 53 within a certain IMSI range be routed to a protected network and anything else be routed to its general network. As a result, two policies (“protect-policy” and “internet-policy”) need to be configured for this customer's routing demands.

a> Identifier protect-policy Priority 2 Match-field IMSI Match-type prefix Match-value 3101501234 Routing-policy-list subnet-profile Routing-policy-select b> Identifier internet-policy Priority 20 Match-field none Match-type Match-value Routing-policy-list ip-profile Routing-policy-select

When a UE 53 registers with SG 60 with an IMSI beginning with “3101501234”, its traffic would match policy “protect-policy” and its traffic would be routed to the protected network defined by “subnet-profile”. Again, traffic from other UEs would be routed by policy “internet-policy”.

FIG. 17 is a flow diagram of the functionality of Wi-Fi offload module 16 of FIG. 2 when performing a flexible routing policy for Wi-Fi offloaded data in accordance with embodiments of the present invention.

At 1702, a data packet is received from a UE. The data packet was offload from a cellular network onto a Wi-Fi network via a Wi-Fi access point, as disclosed in FIG. 16 above. The data packet has an associated APN and an associated IP address.

At 1704, the data packet is evaluated based on two or more defined routing policies, with each routing policy having a routing criteria and a priority. The routing criteria can be based on an identifier of the data packet, such as its APN or IP address. Each routing policy routes the data packet to a different destination, such as a GGSN server or to an Internet router.

At 1704, based on the routing policy and the priority, the data packet is routed to one of at least two different possible destinations.

In one example embodiment, for a specific deployment, four policies are configured in a routing realm: (1) APN routing for foo1.com and route traffic to GGSN1 with priority=10; (2) IMSI routing for prefix “12345” and route traffic to GGSN2 with priority=20; (3) APN routing with regex matching for “foo*.com” and route traffic to GGSN3 with priority=30; (4) default route (no match) to a gateway (“GW”) with priority=40. With the above policies, for a UE with an APN=foo1.com, its traffic would be routed to GGSN1. For a UE with IMSI=12345999 and its APN is not foo1.com, its traffic would be routed to GGSN2. For any UE with APN=foo555 and its IMSI, if present, does not have the prefix of 12345, its traffic would be routed to GGSN3. For any UE which has an APN that does not match policy 1 or policy 3 and its IMSI, if present, does not has the prefix of 12345, its traffic would be routed to the GW. As a result, by configuring different policies with different routing criteria and priorities, a UE's traffic can be routed flexibly. With new applications emerging for UEs, new routing criteria can be defined and be used to route this new traffic.

As disclosed, embodiments provide a flexible policy based selective offload. Parameters returned from the policy server or the information contained in the data packets of Wi-Fi offloaded data is used to make selective offload decisions. For example, as described above, a UE's APN, IMSI, MSISDN, QOS profile, and optionally a UE's IP can be obtained from the policy server and can be configured in a sg-policy for routing. Therefore, intelligent routing of data traffic directly to the Internet or to the GGSN (i.e., mobile core) is provided. Further, as disclosed, embodiments provide flexible IP address management, optional IPSec protection, high performance, unique 1:1 redundancy and accounting support.

Several embodiments are specifically illustrated and/or described herein. However, it will be appreciated that modifications and variations of the disclosed embodiments are covered by the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention. 

What is claimed is:
 1. A non-transitory computer-readable medium having instructions stored thereon that, when executed by a processor, cause the processor to flexibly route Wi-Fi offloaded data at a gateway, the routing comprising: receiving at the gateway a Wi-Fi offloaded data packet from a user equipment via an access point of a Wi-Fi network, the Wi-Fi offloaded data packet comprising an access point name (APN) and an Internet Protocol (IP) address; defining two or more routing policies, each routing policy comprising a routing criteria and a priority and each routing policy routing the Wi-Fi offloaded data packet to a different destination; evaluating at the gateway the Wi-Fi offloaded data packet based on each of the defined routing policies; selecting at the gateway a destination for the Wi-Fi offloaded data packet based on the evaluation of the Wi-Fi offloaded data packet and the routing policies, including the APN and the IP address, wherein the destination comprises an Internet or a cellular operator's core network; and routing from the gateway the Wi-Fi offloaded data packet to the selected destination based on the evaluated routing policies and the relative priorities of the routing policies.
 2. The non-transitory computer-readable medium of claim 1, wherein the data packet is routed to the cellular operator's core network by the gateway via a gateway general packet radio service support node (GGSN) server.
 3. The non-transitory computer-readable medium of claim 1, wherein the data packet is routed to the Internet by the gateway via an Internet router.
 4. The non-transitory computer-readable medium of claim 2, wherein the data packet is routed to the GGSN server via a GPRS tunneling protocol (GTP) tunnel.
 5. The non-transitory computer-readable medium of claim 1, wherein the routing criteria is based on parameters returned from an authentication, authorization and accounting (AAA) policy server.
 6. The non-transitory computer-readable medium of claim 5, wherein the parameters comprise at least one of the APN, an International Mobile Subscriber Identity (IMSI) or the IP address.
 7. The non-transitory computer-readable medium of claim 1, wherein receiving the data packet comprises: receiving a dynamic host configuration protocol (DHCP) message from the access point; converting the DHCP message into an authentication, authorization and accounting (AAA) access request and sending the AAA access request to an AAA policy server; receiving an AAA access accept from the AAA policy server; and initiating a gateway general packet radio service (GPRS) tunneling protocol (GTP) tunnel setup with a GPRS setup node (GGSN).
 8. A method for flexibly routing Wi-Fi offloaded data at a gateway, the method comprising: receiving at the gateway a Wi-Fi offloaded data packet from a user equipment via an access point of a Wi-Fi network, the Wi-Fi offloaded data packet comprising an access point name (APN) and an Internet Protocol (IP) address; defining two or more routing policies, each routing policy comprising a routing criteria and a priority and each routing policy routing the Wi-Fi offloaded data packet to a different destination; evaluating at the gateway the Wi-Fi offloaded data packet based on each of the defined routing policies; selecting at the gateway a destination for the Wi-Fi offloaded data packet based on the evaluation of the Wi-Fi offloaded data packet and the routing policies, including the APN and the IP address, wherein the destination comprises an Internet or a cellular operator's core network; and routing from the gateway the Wi-Fi offloaded data packet to the selected destination based on the evaluated routing policies and the relative priorities of the routing policies.
 9. The method of claim 8, wherein the data packet is routed to the cellular operator's core network by the gateway via a gateway general packet radio service support node (GGSN) server.
 10. The method of claim 8, wherein the data packet is routed to the Internet by the gateway via an Internet router.
 11. The method of claim 9, wherein the data packet is routed to the GGSN server via a GPRS tunneling protocol (GTP) tunnel.
 12. The method of claim 8, wherein the routing criteria is based on parameters returned from an authentication, authorization and accounting (AAA) policy server.
 13. The method of claim 12, wherein the parameters comprise at least one of the APN, an International Mobile Subscriber Identity (IMSI) or the IP address.
 14. The method of claim 8, wherein receiving the data packet comprises: receiving a dynamic host configuration protocol (DHCP) message from the access point; converting the DHCP message into an authentication, authorization and accounting (AAA) access request and sending the AAA access request to an AAA policy server; receiving an AAA access accept from the AAA policy server; and initiating a gateway general packet radio service (GPRS) tunneling protocol (GTP) tunnel setup with a GPRS setup node (GGSN).
 15. A flexible router for Wi-Fi offloaded data, the router comprising: a processor; a non-transitory storage device coupled to the processor that stores a Wi-Fi offload module and two or more routing policies, each routing policy comprising a routing criteria and a priority and each routing policy routing a Wi-Fi offloaded data packet to a different destination; wherein the Wi-Fi offload module, when executed by the processor, receives the Wi-Fi offloaded data packet from a user equipment via an access point of a Wi-Fi network, the Wi-Fi offloaded data packet comprising an access point name (APN) and an Internet Protocol (IP) address; evaluates the Wi-Fi offloaded data packet based on each of the defined routing policies; selects a destination for the Wi-Fi offloaded data packet based on the evaluation of the Wi-Fi offloaded data packet and the routing policies, including the APN and the IP address, wherein the destination comprises an Internet or a cellular operator's core network; and routes the Wi-Fi offloaded data packet to the selected destination based on the evaluated routing policies and the relative priorities of the routing policies.
 16. The flexible router of claim 15, wherein the data packet is routed to the cellular operator's core network by the gateway via a gateway general packet radio service support node (GGSN) server.
 17. The flexible router of claim 15, wherein the data packet is routed to the Internet via an Internet router.
 18. The flexible router of claim 15, wherein the routing criteria is based on parameters returned from an authentication, authorization and accounting (AAA) policy server.
 19. The flexible router of claim 16, wherein the data packet is routed to the GGSN server via a GPRS tunneling protocol (GTP) tunnel.
 20. The flexible router of claim 15, wherein the Wi-Fi offload module further: receives a dynamic host configuration protocol (DHCP) message from the access point; converts the DHCP message into an authentication, authorization and accounting (AAA) access request and sending the AAA access request to an AAA policy server; receives an AAA access accept from the AAA policy server; and initiates a gateway general packet radio service (GPRS) tunneling protocol (GTP) tunnel setup with a GPRS setup node (GGSN). 